Grannoms build square-shaped cases and live in riffly water or runs with moderate to fast currents. Larvae are sometimes knocked loose, so a cased caddis pattern dead-drifted near the bottom might pick up some fish.
Pupation occurs in the same water that the larvae lived in. During a hatch, dead-drift a pupa pattern near the bottom in riffly water or just below riffles. An unweighted pupa pattern can also be drifted near the surface, or you can present a Soft Hackle with wet-fly swing. Another good strategy is a dry fly with a pupa pattern as a dropper or trailer; the dry fly acts as an indicator and sometimes is taken by the trout.
After the hatch, errant and unlucky adults fall onto the water, and a dry fly is the right choice. Bankwater downwind or downstream from overhanging trees is a good place to cast your dry.
Female grannoms swim or crawl underwater to lay eggs. You can fish a dry at this time, or go subsurface with a Soft Hackle or Diving Caddis pattern.
Grannoms hatch in spring and fall. The fall adults are smaller and are usually black, hence their nickname, "black caddis."
Articles About Grannoms
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Grannoms Grannoms are an important caddis family that is common in Western waters. They are especially important in spring and fall. But what do they have to do with your mother?
Caddis Larvae--Part I Imitations of caddis adults and pupae are staples of a well-stocked Western fly box, but larva imitations are generaly absent. And the rare angler that carries larva patterns usually has the wrong ones.